Analysis of Epichlorohydrin in Drinking Water

Importance of the Topic

Epichlorohydrin is a widely used intermediate in polymer and pharmaceutical production but poses significant health risks due to its toxicity and reactivity. Regulatory bodies such as the European Union and the US EPA require ultra-low detection limits in drinking water to protect public health, driving the need for sensitive and reliable analytical methods.

Objectives and Study Overview

The study aimed to develop and validate a purge-and-trap GC/MS method for quantifying epichlorohydrin in drinking water at minimum detection limits of 30 parts per trillion. The work evaluated calibration performance, method detection limits, accuracy, precision, and long-term robustness using advanced instrumentation.

Methodology and Instrumentation

Sample preparation involved spiking drinking water with epichlorohydrin standards (10–500 ppt) and an internal standard (1,4-difluorobenzene at 200 ppt). An eight-point calibration curve (R² ≥ 0.995) was generated. The Tekmar Atomx XYZ P&T concentrator featured efficient trap cooling and moisture control to reduce interferences. GC separation was performed on an Agilent DB-624 UI column with a temperature program from 40 °C to 220 °C. Detection employed an Agilent 5977C MSD in selected ion monitoring mode targeting ions m/z 57, 62, and 49.

Main Results and Discussion

Calibration linearity exceeded method requirements (R² = 0.9997). The method detection limit was determined at 4.4 ppt with precision of 4.7 % and accuracy of 99 % at 30 ppt. Mid-point calibration checks at 100 ppt yielded precision of 3 % and accuracy of 93 %. A long-term study of 40 sequential 30 ppt samples demonstrated 4.3 % precision and 92 % accuracy, satisfying regulatory criteria. Representative chromatograms confirmed clear resolution of epichlorohydrin and internal standard peaks.

Benefits and Practical Applications

• Achieves sub-30 ppt detection for regulatory compliance in drinking water testing.
• Automated purge-and-trap workflow increases sample throughput and reproducibility.
• Robust method suitable for routine QA/QC in water analysis laboratories.

Future Trends and Potential Applications

• Integration with high-resolution mass spectrometry for improved selectivity.
• Expansion to other trace volatile organic contaminants in environmental matrices.
• Further automation of data processing and reporting for high-throughput testing.

Conclusion

The optimized Tekmar Atomx XYZ P&T and Agilent GC/MSD method reliably quantifies epichlorohydrin at ultra-trace levels in drinking water. It meets stringent regulatory limits with excellent linearity, sensitivity, and long-term stability, offering a robust solution for environmental and QA/QC laboratories.

Reference

• Lucentini L, Ferretti E, Veschetti E, Sibio V, Citti G, Ottaviani M. Static Headspace And Purge-and-Trap Gas Chromatography for Epichlorohydrin Determination in Drinking Water. Microchemical Journal 2005, 80(1), 89–98.
• Mattioda C. Low-Level Analysis of Epichlorohydrin in Drinking Water by Headspace Trap-GC/MS. Perkin Elmer Field Application Report 2008.
• Sram RJ, Landa L, Samkova I. Effect of Occupational Exposure to Epichlorohydrin on the Frequency of Chromosome Aberrations in Peripheral Lymphocytes. Mutation Research 1983, 122(1), 59.
• Council Directive of 83 November 1998. Official Journal of the European Communities 1998, No. 330/32.